Re: [dpdk-dev] [PATCH] net/ixgbe: add support of loopback for X540/X550

["Meunier, Julien (Nokia - FR/Paris-Saclay)" <julien.meunier@nokia.com>]

Hi,

Mmm, you're right. However, as like for the 82599, the pmd skips the 
link configuration, so, it should not enable the autoneg.

During my tests, I had a 10G connectivity, and I didn't notice any 
problem. I used the DPDK application "test", with the test 
pmd_perf_autotest.

Should I need to modify my code to be sure that autoneg is disabled (and 
force it to 10G) ?

Thanks,
Best regards,
Julien Meunier

On 07/01/2019 07:53, Zhang, Qi Z wrote:
> 
> 
>> -----Original Message-----
>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Julien Meunier
>> Sent: Thursday, January 3, 2019 12:01 AM
>> To: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Lu, Wenzhuo
>> <wenzhuo.lu@intel.com>
>> Cc: dev@dpdk.org
>> Subject: [dpdk-dev] [PATCH] net/ixgbe: add support of loopback for X540/X550
>>
>> Loopback mode is also supported on X540 and X550 NICs, according to their
>> datasheet (section 15.2). The way to set it up is a little different of the 82599.
> 
> Thanks for enable this.
> 
> one question is, Datasheet also mentioned that auto negotiation should be disabled
> but I didn't see any related change with it.
> 
> Would you share more insight on this?
> 
>>
>> Signed-off-by: Julien Meunier <julien.meunier@nokia.com>
>> ---
>>   drivers/net/ixgbe/ixgbe_ethdev.c | 10 ++++++---
>> drivers/net/ixgbe/ixgbe_ethdev.h |  5 ++---
>>   drivers/net/ixgbe/ixgbe_rxtx.c   | 47
>> ++++++++++++++++++++++++++++++++++------
>>   3 files changed, 49 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
>> b/drivers/net/ixgbe/ixgbe_ethdev.c
>> index 7493110..7eb3303 100644
>> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
>> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
>> @@ -2652,9 +2652,13 @@ ixgbe_dev_start(struct rte_eth_dev *dev)
>>   		goto error;
>>   	}
>>
>> -	/* Skip link setup if loopback mode is enabled for 82599. */
>> -	if (hw->mac.type == ixgbe_mac_82599EB &&
>> -			dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_82599_TX_RX)
>> +	/* Skip link setup if loopback mode is enabled. */
>> +	if ((hw->mac.type == ixgbe_mac_82599EB ||
>> +	     hw->mac.type == ixgbe_mac_X540 ||
>> +	     hw->mac.type == ixgbe_mac_X550 ||
>> +	     hw->mac.type == ixgbe_mac_X550EM_x ||
>> +	     hw->mac.type == ixgbe_mac_X550EM_a) &&
>> +			dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_TX_RX)
>>   		goto skip_link_setup;
>>
>>   	if (ixgbe_is_sfp(hw) && hw->phy.multispeed_fiber) { diff --git
>> a/drivers/net/ixgbe/ixgbe_ethdev.h b/drivers/net/ixgbe/ixgbe_ethdev.h
>> index 565c69c..c60a697 100644
>> --- a/drivers/net/ixgbe/ixgbe_ethdev.h
>> +++ b/drivers/net/ixgbe/ixgbe_ethdev.h
>> @@ -65,9 +65,8 @@
>>   #define IXGBE_QUEUE_ITR_INTERVAL_DEFAULT	500 /* 500us */
>>
>>   /* Loopback operation modes */
>> -/* 82599 specific loopback operation types */
>> -#define IXGBE_LPBK_82599_NONE   0x0 /* Default value. Loopback is disabled.
>> */
>> -#define IXGBE_LPBK_82599_TX_RX  0x1 /* Tx->Rx loopback operation is
>> enabled. */
>> +#define IXGBE_LPBK_NONE   0x0 /* Default value. Loopback is disabled. */
>> +#define IXGBE_LPBK_TX_RX  0x1 /* Tx->Rx loopback operation is enabled.
>> +*/
>>
>>   #define IXGBE_MAX_JUMBO_FRAME_SIZE      0x2600 /* Maximum Jumbo
>> frame size. */
>>
>> diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
>> index 9a79d18..0ef7fdf 100644
>> --- a/drivers/net/ixgbe/ixgbe_rxtx.c
>> +++ b/drivers/net/ixgbe/ixgbe_rxtx.c
>> @@ -4879,10 +4879,14 @@ ixgbe_dev_rx_init(struct rte_eth_dev *dev)
>>   		hlreg0 &= ~IXGBE_HLREG0_JUMBOEN;
>>
>>   	/*
>> -	 * If loopback mode is configured for 82599, set LPBK bit.
>> +	 * If loopback mode is configured, set LPBK bit.
>>   	 */
>> -	if (hw->mac.type == ixgbe_mac_82599EB &&
>> -			dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_82599_TX_RX)
>> +	if ((hw->mac.type == ixgbe_mac_82599EB ||
>> +	     hw->mac.type == ixgbe_mac_X540 ||
>> +	     hw->mac.type == ixgbe_mac_X550 ||
>> +	     hw->mac.type == ixgbe_mac_X550EM_x ||
>> +	     hw->mac.type == ixgbe_mac_X550EM_a) &&
>> +			dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_TX_RX)
>>   		hlreg0 |= IXGBE_HLREG0_LPBK;
>>   	else
>>   		hlreg0 &= ~IXGBE_HLREG0_LPBK;
>> @@ -5088,6 +5092,29 @@ ixgbe_setup_loopback_link_82599(struct ixgbe_hw
>> *hw)
>>   	msec_delay(50);
>>   }
>>
>> +/*
>> + * Set up link loopback for X540 / X550 mode Tx->Rx.
>> + */
>> +static inline void __attribute__((cold))
>> +ixgbe_setup_loopback_link_x540_x550(struct ixgbe_hw *hw) {
>> +	uint32_t macc;
>> +	PMD_INIT_FUNC_TRACE();
>> +
>> +	/* datasheet 15.2.1: MACC.FLU = 1 (force link up) */
>> +	macc = IXGBE_READ_REG(hw, IXGBE_MACC);
>> +	macc |= IXGBE_MACC_FLU;
>> +	IXGBE_WRITE_REG(hw, IXGBE_MACC, macc);
>> +
>> +	/* Restart link */
>> +	IXGBE_WRITE_REG(hw,
>> +			IXGBE_AUTOC,
>> +			IXGBE_AUTOC_LMS_10G_LINK_NO_AN | IXGBE_AUTOC_FLU);
>> +
>> +	hw->mac.ops.release_swfw_sync(hw, IXGBE_GSSR_MAC_CSR_SM);
>> +	msec_delay(50);
>> +}
>> +
>>
>>   /*
>>    * Start Transmit and Receive Units.
>> @@ -5148,10 +5175,16 @@ ixgbe_dev_rxtx_start(struct rte_eth_dev *dev)
>>   	rxctrl |= IXGBE_RXCTRL_RXEN;
>>   	hw->mac.ops.enable_rx_dma(hw, rxctrl);
>>
>> -	/* If loopback mode is enabled for 82599, set up the link accordingly */
>> -	if (hw->mac.type == ixgbe_mac_82599EB &&
>> -			dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_82599_TX_RX)
>> -		ixgbe_setup_loopback_link_82599(hw);
>> +	/* If loopback mode is enabled, set up the link accordingly */
>> +	if (dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_TX_RX) {
>> +		if (hw->mac.type == ixgbe_mac_82599EB)
>> +			ixgbe_setup_loopback_link_82599(hw);
>> +		else if (hw->mac.type == ixgbe_mac_X540 ||
>> +		     hw->mac.type == ixgbe_mac_X550 ||
>> +		     hw->mac.type == ixgbe_mac_X550EM_x ||
>> +		     hw->mac.type == ixgbe_mac_X550EM_a)
>> +			ixgbe_setup_loopback_link_x540_x550(hw);
>> +	}
>>
>>   #ifdef RTE_LIBRTE_SECURITY
>>   	if ((dev->data->dev_conf.rxmode.offloads &
>> --
>> 2.10.2
>